Spring structure for furniture



May 16, 1939. M. THUM, 2,158,441

SPRING STRUCTURE FOR FURNITURE Filed April 1, 1958 "T ELEZZZICIIai-EEI F-T:

Patented May 16, 1939 UNiTED STATES 4 Claims.

The present invention relates generally to spring structures for furniture and more particularly to spring supports of that type in which a plurality of parallel inelastic metallic straps are extended substantially across a supporting frame from front to rear, these straps being directly connected at one end to one member of the frame and having their opposite ends connected to the opposite member of the frame through elastic springs, so that the spring structure its supporting functions operates wholly independent of the side members of the frame.

A structure of this general type is. disclosed and claimed in my Patent No. 1,876,101, dated September 6, 1932, wherein upper and lower covering fabrics extending entirely over the straps and their elastic or spring connections, provide pockets in which the straps loosely extend for relative movement lengthwise as well as laterally toward and away from one another. According to this patented structure, therefore, the straps contact the upper fabric throughout their lengths, but the single thickness of this upper fabric exists between the metal straps and a cushion or load disposed on the spring structure.

It is the object of the present invention in general to retain the straps and their spring connections and at the same time substantially economize in the fabric covering, while at the same time increasing the life of the upper fabric.

More particularly in this respect, it is an object of the present invention to substitute for the full low-er covering fabric of my prior patent, a par tial covering fabric layer in the nature of a cross web intermediate the ends of the straps, not only I the straps to further assist in preventing undue wear of the upper fabric and economize in the amount of fabric necessarily used in substantially covering the straps.

With these and other objects in mind, the invention resides in the several features to be now described in detail with reference to the accornpanying drawing, forming a part of this specification, and wherein:

Figure 1 is a top plan view showing the complete spring structure.

Figure 2 is a vertical longitudinal section taken therethrough substantially on line 22 of Figure 1.

Figure 3 is a view similar to Figure 2 with the metallic straps and their spring connections removed.

Figure 4 is a vertical transverse section taken substantially on the line L-ii of Figure l, and

Figure 5 is a detail sectional perspective view showing one of the metallic straps with its spring connections and a portion of the combined upper and lower fabrics through which the strap passes.

Referring now to these figures, the spring structure of the present invention, like that of my prior patent, utilizes a plurality of parallel inelastic flat metallic straps iii, each of which may have its forward downwardly angular end it depending over the front rail of a rectangular frame and secured to this rail as by means of nails, tacks, or other suitable fastening members is. The rear ends of the several straps iii are apertured as at it to receive the forward ends of coil springs 55, and, in the present structure, the rear ends of these springs 55 hook through U- shaped anchoring members it extending inwardly through bores ii in the rear rail it of the frame, with their rear extensions divergently flattened against the outer surface of rail E8 to firmly hold the same for the anchoring of the rear ends of the springs iii and consequently the rear ends of the straps it.

In further accordance with the present invention, a generally rectangular section of a substantial fabric i9 extends above and along the series of straps it, with its forward edge extending downwardly over the front rail l2, to which it may be secured by nails, tacks, or like fastening members 26. Ihe sides of the upper covering fabric 69 are turned under and s 'tched as at to form side pockets 22 for the two side straps it, and it will be noted at this point that the entire series of straps iii with their covering it thus free to move upwardly and downwardly independent of the side rails 23 of the frame.

Along its rear edge, which terminates at the rear ends of the several straps iii, the covering fabric is has a hem 2t and the forward hook ends of the springs iii in their extension through the openings i of the several straps pierce this hem, so that the fabric i9 is in the present instance drawn substantially taut across the upper surfaces of the straps it, the several springs it? being left uncovered.

The lower fabric is in the nature of a cross web 25 of a width substantially less than the length of the upper fabric it, having its ends extending into the side pockets 22 above described and secured by the stitching 2i which forms these pockets.

The web 25 has its edge portions turned up- Wardly and inwardly as appears at 26, and these portions 23 are fastened to the web by rows of stitching 27, which, it will be noted, pass through the material of the lower Web 25 only, the stitching 2'! extending parallel with the edges of the folded web and substantially spaced from said side edges. It is preferable that the folded side portions of the web '25 be also connected by rows of stitching 28 which are immediately adjacent to the side edges of the web.

The lower web is connected to the upper covering fabric [9 by parallel rows of stitching 29, preferably arranged parallel to the side edges of the web 25 inwardly beyond the rows of stitching 28, and thus passing through the two folded side portions of the web as well as the up or covering fabric l9.

Immediately inwardly beyond the rows of stitching 29, the two thicknesses of the Web 25 are pierced by slits of suflicient Width to receive the straps IE3, each strap being passed rearwardly through a slit adjacent to the front edge of the web and then again rearwardly through slit adjacent to the rear edge of the web, so that a portion of each strap extends between the web and the covering fabric for the major portion of the width of the web, leaving the edge portions of the web, consisting as before described of folded layers, lying between portions of the strap and the upper fabric is from the strap receiving slits 36 of web 25 to the web edges.

In this way, those portions of the web lying be tween the straps on the upper fabric serve as cushions at spaced points, which relieve wearing contact to a considerable extent between the straps and the upper fabric.

It is obvious that since the straps are thus threaded through the front and rear portions of the web 25, the latter serves as a lateral guide to prevent lateral shifting of the straps to any great extent in the series, and the cushions or buffers provided by this construction between the straps and the upper fabric, coupled with the support of the upper fabric tautly across and above the straps, relieve the spring structure a whole from undue wear and not only permits of economy in the amount of fabric necessary in the first instance for the accomplishment of its purposes, but provides for substantially greater life of the fabric that is necessary to be used.

What is claimed is:

1. A spring structure of the character set forth including a frame, a plurality of parallel inelastic metallic straps extending across the frame and rigidly in connection at one end with one of the frame members, a series of elastic springs in connection with the opposite ends of the straps and connecting the same with the opposite frame member, a fabric overlying the said straps having an edge thereof secured to the first-mentioned frame member and having its opposite edge engaged and held by the said spring members at the spring engaged ends of the straps, and a web crossing the lower surface of said fabric and secured thereto intermediate the ends of the straps, said web having guide openings through which the straps extend at spaced points in the lengths of the straps, and said web having portions thereof also at spaced points in the lengths of the straps interposed between the latter and the upper fabric.

2. In a spring structure including a supporting frame, a plurality of parallel inelastic metallic straps anchored at one end to a portion of said frame, and having controlling spring members in connection with the opposite ends thereof and in connection with an opposite portion of the frame, a fabric overlying the said straps and having one edge thereof securely fastened to the frame adjacent to the anchored ends of the straps and having its opposite edge engaged by the said spring members adjacent to the opposite ends of the straps, and a cross web transversely of and below the straps intermediate the ends of the latter, having guide openings through which the straps extend at points spaced apart in the lengths of the latter, said cross web having edge portions interposed between the straps and the upper fabric and secured to the latter.

3. In a spring structure including a supporting frame, a plurality of parallel inelastic straps securely anchored at one end to a portion of said frame, a plurality of flexible spring members engaging the opposite ends of said straps and in connection with an opposite portion of the frame, an upper fabric overlying the several st s, having one edge thereof secured to the frame adjacent to the anchored ends of the straps and having the opposite edge thereof engaged by said spring members, and a guide web extending transversely beneath the straps intermediate the ends of the latter having its edge portions folded over iereon to provide a double thickness, said edge portions having openings through which the straps extend at spaced points in the lengths of the latter and having portions beyond the openings interposed between the straps and the upper fabric and secured to the latter.

4. In a spring structure including a supporting frame, a plurality of parallel inelastic straps anchored at one end to a portion of said frame, and a plurality of flexible spring members engaging the opposite ends of said. straps and in connection with an opposite portion of the frame, upper fabric overlying the straps having one edge securelg fastened to the frame adjacent to the anchored ends of the straps and having its opposite edge engaged said spring members, and a guide web extending l, isversely of the several straps int "nediar-e th ends of latter, having guide on ings throu which the straps extend and having portions below the s and other portions interposed between the straps and the upper fabric and secured to the latter.

MARTIN THUM. 

